diff options
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/include/asm/assembler.h | 23 | ||||
| -rw-r--r-- | arch/arm64/kernel/entry.S | 73 |
2 files changed, 42 insertions, 54 deletions
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index fd3e3924041b..5901480bfdca 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -21,6 +21,7 @@ #endif #include <asm/ptrace.h> +#include <asm/thread_info.h> /* * Stack pushing/popping (register pairs only). Equivalent to store decrement @@ -68,23 +69,31 @@ msr daifclr, #8 .endm - .macro disable_step, tmp + .macro disable_step_tsk, flgs, tmp + tbz \flgs, #TIF_SINGLESTEP, 9990f mrs \tmp, mdscr_el1 bic \tmp, \tmp, #1 msr mdscr_el1, \tmp + isb // Synchronise with enable_dbg +9990: .endm - .macro enable_step, tmp + .macro enable_step_tsk, flgs, tmp + tbz \flgs, #TIF_SINGLESTEP, 9990f + disable_dbg mrs \tmp, mdscr_el1 orr \tmp, \tmp, #1 msr mdscr_el1, \tmp +9990: .endm - .macro enable_dbg_if_not_stepping, tmp - mrs \tmp, mdscr_el1 - tbnz \tmp, #0, 9990f - enable_dbg -9990: +/* + * Enable both debug exceptions and interrupts. This is likely to be + * faster than two daifclr operations, since writes to this register + * are self-synchronising. + */ + .macro enable_dbg_and_irq + msr daifclr, #(8 | 2) .endm /* diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 39ac630d83de..e8b23a3b68d0 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -60,6 +60,9 @@ push x0, x1 .if \el == 0 mrs x21, sp_el0 + get_thread_info tsk // Ensure MDSCR_EL1.SS is clear, + ldr x19, [tsk, #TI_FLAGS] // since we can unmask debug + disable_step_tsk x19, x20 // exceptions when scheduling. .else add x21, sp, #S_FRAME_SIZE .endif @@ -259,7 +262,7 @@ el1_da: * Data abort handling */ mrs x0, far_el1 - enable_dbg_if_not_stepping x2 + enable_dbg // re-enable interrupts if they were enabled in the aborted context tbnz x23, #7, 1f // PSR_I_BIT enable_irq @@ -275,6 +278,7 @@ el1_sp_pc: * Stack or PC alignment exception handling */ mrs x0, far_el1 + enable_dbg mov x1, x25 mov x2, sp b do_sp_pc_abort @@ -282,6 +286,7 @@ el1_undef: /* * Undefined instruction */ + enable_dbg mov x0, sp b do_undefinstr el1_dbg: @@ -294,10 +299,11 @@ el1_dbg: mrs x0, far_el1 mov x2, sp // struct pt_regs bl do_debug_exception - + enable_dbg kernel_exit 1 el1_inv: // TODO: add support for undefined instructions in kernel mode + enable_dbg mov x0, sp mov x1, #BAD_SYNC mrs x2, esr_el1 @@ -307,7 +313,7 @@ ENDPROC(el1_sync) .align 6 el1_irq: kernel_entry 1 - enable_dbg_if_not_stepping x0 + enable_dbg #ifdef CONFIG_TRACE_IRQFLAGS bl trace_hardirqs_off #endif @@ -332,8 +338,7 @@ ENDPROC(el1_irq) #ifdef CONFIG_PREEMPT el1_preempt: mov x24, lr -1: enable_dbg - bl preempt_schedule_irq // irq en/disable is done inside +1: bl preempt_schedule_irq // irq en/disable is done inside ldr x0, [tsk, #TI_FLAGS] // get new tasks TI_FLAGS tbnz x0, #TIF_NEED_RESCHED, 1b // needs rescheduling? ret x24 @@ -349,7 +354,7 @@ el0_sync: lsr x24, x25, #ESR_EL1_EC_SHIFT // exception class cmp x24, #ESR_EL1_EC_SVC64 // SVC in 64-bit state b.eq el0_svc - adr lr, ret_from_exception + adr lr, ret_to_user cmp x24, #ESR_EL1_EC_DABT_EL0 // data abort in EL0 b.eq el0_da cmp x24, #ESR_EL1_EC_IABT_EL0 // instruction abort in EL0 @@ -378,7 +383,7 @@ el0_sync_compat: lsr x24, x25, #ESR_EL1_EC_SHIFT // exception class cmp x24, #ESR_EL1_EC_SVC32 // SVC in 32-bit state b.eq el0_svc_compat - adr lr, ret_from_exception + adr lr, ret_to_user cmp x24, #ESR_EL1_EC_DABT_EL0 // data abort in EL0 b.eq el0_da cmp x24, #ESR_EL1_EC_IABT_EL0 // instruction abort in EL0 @@ -423,11 +428,8 @@ el0_da: */ mrs x0, far_el1 bic x0, x0, #(0xff << 56) - disable_step x1 - isb - enable_dbg // enable interrupts before calling the main handler - enable_irq + enable_dbg_and_irq mov x1, x25 mov x2, sp b do_mem_abort @@ -436,11 +438,8 @@ el0_ia: * Instruction abort handling */ mrs x0, far_el1 - disable_step x1 - isb - enable_dbg // enable interrupts before calling the main handler - enable_irq + enable_dbg_and_irq orr x1, x25, #1 << 24 // use reserved ISS bit for instruction aborts mov x2, sp b do_mem_abort @@ -448,6 +447,7 @@ el0_fpsimd_acc: /* * Floating Point or Advanced SIMD access */ + enable_dbg mov x0, x25 mov x1, sp b do_fpsimd_acc @@ -455,6 +455,7 @@ el0_fpsimd_exc: /* * Floating Point or Advanced SIMD exception */ + enable_dbg mov x0, x25 mov x1, sp b do_fpsimd_exc @@ -463,11 +464,8 @@ el0_sp_pc: * Stack or PC alignment exception handling */ mrs x0, far_el1 - disable_step x1 - isb - enable_dbg // enable interrupts before calling the main handler - enable_irq + enable_dbg_and_irq mov x1, x25 mov x2, sp b do_sp_pc_abort @@ -475,9 +473,9 @@ el0_undef: /* * Undefined instruction */ - mov x0, sp // enable interrupts before calling the main handler - enable_irq + enable_dbg_and_irq + mov x0, sp b do_undefinstr el0_dbg: /* @@ -485,11 +483,13 @@ el0_dbg: */ tbnz x24, #0, el0_inv // EL0 only mrs x0, far_el1 - disable_step x1 mov x1, x25 mov x2, sp - b do_debug_exception + bl do_debug_exception + enable_dbg + b ret_to_user el0_inv: + enable_dbg mov x0, sp mov x1, #BAD_SYNC mrs x2, esr_el1 @@ -500,15 +500,12 @@ ENDPROC(el0_sync) el0_irq: kernel_entry 0 el0_irq_naked: - disable_step x1 - isb enable_dbg #ifdef CONFIG_TRACE_IRQFLAGS bl trace_hardirqs_off #endif irq_handler - get_thread_info tsk #ifdef CONFIG_TRACE_IRQFLAGS bl trace_hardirqs_on @@ -517,14 +514,6 @@ el0_irq_naked: ENDPROC(el0_irq) /* - * This is the return code to user mode for abort handlers - */ -ret_from_exception: - get_thread_info tsk - b ret_to_user -ENDPROC(ret_from_exception) - -/* * Register switch for AArch64. The callee-saved registers need to be saved * and restored. On entry: * x0 = previous task_struct (must be preserved across the switch) @@ -563,10 +552,7 @@ ret_fast_syscall: ldr x1, [tsk, #TI_FLAGS] and x2, x1, #_TIF_WORK_MASK cbnz x2, fast_work_pending - tbz x1, #TIF_SINGLESTEP, fast_exit - disable_dbg - enable_step x2 -fast_exit: + enable_step_tsk x1, x2 kernel_exit 0, ret = 1 /* @@ -585,7 +571,6 @@ work_pending: bl do_notify_resume b ret_to_user work_resched: - enable_dbg bl schedule /* @@ -596,9 +581,7 @@ ret_to_user: ldr x1, [tsk, #TI_FLAGS] and x2, x1, #_TIF_WORK_MASK cbnz x2, work_pending - tbz x1, #TIF_SINGLESTEP, no_work_pending - disable_dbg - enable_step x2 + enable_step_tsk x1, x2 no_work_pending: kernel_exit 0, ret = 0 ENDPROC(ret_to_user) @@ -625,12 +608,8 @@ el0_svc: mov sc_nr, #__NR_syscalls el0_svc_naked: // compat entry point stp x0, scno, [sp, #S_ORIG_X0] // save the original x0 and syscall number - disable_step x16 - isb - enable_dbg - enable_irq + enable_dbg_and_irq - get_thread_info tsk ldr x16, [tsk, #TI_FLAGS] // check for syscall tracing tbnz x16, #TIF_SYSCALL_TRACE, __sys_trace // are we tracing syscalls? adr lr, ret_fast_syscall // return address |